Worried and scared

Sam
My period is due on the second of Jan but it's come early, at first I thought it was spotting, but now this is the third day of blood it just comes at a random time and this is the first time today, it started four days ago but the first time was more brown and not bloody at all, yesterday and the day before was bloody but today it's a mucus type of blood and I'm worried it could be something more serious, anybody got any advice the same thing happens last month